What is the dating of the earliest Syriac manuscript of the Hebrew Tanakh (Old Testament)? What is the dating of the earliest Syriac manuscript of the New Testament? Who is in current possession of these manuscripts?
The oldest extant New Testament text appears to be the Syriac Sinaitic a collection of gospels in the Old Syriac textual tradition dated to the 4th century. The oldest extant Old Testament text dates to the 5th century. These are about as old as the earliest Greek texts, and much older than all extant Hebrew texts except for the Dead Sea Scrolls.
There are several different Syriac New Testament textual traditions: the Old Syriac (gospels only), the Peshitta (the whole New Testament except 2 Peter, 2&3 John, and Revelation), and the Diatessaron (a gospel harmony).
The Old Syriac: The oldest extant manuscripts of the Old Syriac gospels are the Syriac Sinaitic and the Curetonian Gospels. The Syriac Sinaitic is a palimpsest (that is a text where the original was scraped off and another text written on top) found at St. Catherine's Monastery on the Sinai peninsula (the same location as the more famous Codex Sinaiticus). It has been dated paleographically to the mid to late 4th century. The Curetonian gospels have been dated paleographically to the early 5th century. This tradition is widely believed to date back to the late 2nd century, and appears in the quotations in the writings of St. Ephrem an Eastern church father in the from the 4th century. The writings of St. Ephrem suggest that there were Old Syriac versions of Acts and the letters of Paul, but there are no extant original texts.
Peshitta The textual tradition with the greatest number of manuscripts is the Peshitta, which was the standard text of the Eastern church since at least the early 5th century. The oldest extant text is dated by colophon (that is the scribe wrote the date) to 534 AD. There are several other 6th century texts, some of which may be slightly earlier (e.g. this manuscript).
Diatessaron Sometime between 160 and 175 AD, Tatian made a gospel harmony called the Diatessaron. Although this is not considered canonical now (and was declared heretical in the 5th century) it was the standard version of the gospels used in many eastern churches in the 3rd and 4th centuries. It is unknown whether it was translated from a Greek harmony or written directly in Syriac. Although we have many ancient references to the Diatessaron and quotations of its contents, there are no complete extant texts.
The Peshitta Old Testament was translated directly from Hebrew with some influence from Aramaic commentaries called Targums. This translation is believed to have taken place in roughly the first century AD. The oldest extant manuscript dates to the late 5th century (London, British Library, Add. 14,425).
Earliest "surviving" Aramaic manuscript (a.k.a Syriac) dates to 5th century AD (Syriac manuscript # 14,470) which is available at British Library. Many of the earliest Aramaic manuscripts were destroyed.
For Example, Archbishop Menezies succeeded in destroying ancient Aramaic manuscipts (includes OT and NT) which was preserved in Kerala (South India) until early 1600s. Because of this, there are south indian christians who dislike European Christians.
The Khabouris Manuscript (11th century Aramaic Peshitta NT manuscript) is a copy of a Second Century New Testament, which was written in approximately 165 AD. Aramaic and Hebrew scribes usually annotate their copy with a notation that identifies the source document they copied. The annotation is called a "colophon". The colophon in the Khabouris Codex identifies its SOURCE as a document that existed about 165 CE.
When Khabouris Manuscript was found, the news article "US Library gets an Ancient Bible" appeared in the New York Times on March 26, 1955 reporting on the oldest known New Testament Bible written in the language "used by Christ". The article noted how it was taken to the White House where President Eisenhower viewed it. The Bible was said to be insured for "an hour and a half" in the amount of $1,500,000 US dollars. When the Khabouris Codex was first revealed to America in April 1955 it was referred to as "the NT Time Bomb."
Here is a website that explains about Aramaic Peshitta Tanakh (Aramaic OT) from first century AD.
Information about Aramaic Eastern Peshitta (Aramaic NT) are available at the below website. You may contact Aramaic scholars at the below website for more information on Aramaic Peshitta NT.